Understanding the Structure and Dynamics of Surfactant Adsorption at Mineral/Water Interfaces
نویسنده
چکیده
Self-assembly of surface-active agents at solid–liquid interfaces is critical for many processes in nature and technology, including the stability of suspension, detergency, wetting and mineral separation. Historically, a detailed understanding of nanometerscale layers has emerged. However, surprisingly little is known about their dynamics—the key to non-equilibrium phenomena. Even in equilibrium, there is constant exchange of monomers between bulk and monolayer. Determination of the associated rate constants has been undertaken by evaluating adsorption and desorption kinetics. These methods are not practical near equilibrium adsorption as they rely upon a changing surface concentration. Hence, little can be learned about the true equilibrium state of a monolayer. This presentation describes the uses vibrational sum frequency spectroscopy to probe the monomer exchange dynamics of self-assembled surfactants under equilibrium conditions at the calcium fluoride/water interface. C O -O C O -O
منابع مشابه
In situ non-linear spectroscopic approaches to understanding adsorption at mineral–water interfaces
Over the last decades, significant advances have been made in the study of adsorption processes at mineral–water interfaces. In particular, surface-enhanced infrared (IR) techniques, and, more recently, non-linear vibrational sum-frequency spectroscopy have provided novel insights into the structure and dynamics of these interfaces. The driving forces behind adsorption at mineral substrates are...
متن کاملMolecular Dynamics Simulations of Protein Adsorption at Interfaces
Proteins can often adsorb irreversibly at fluid/fluid interfaces; the understanding of the adsorption mechanism has relevance across a variety of industrial (e.g. the creation of stable emulsions) and biological (e.g. biofilm formation) processes. I performed molecular dynamics simulations of two surfactant proteins as they interact with air/water and oil/water interfaces, describing the origin...
متن کاملMonomer exchange dynamics of self-assembled surfactant monolayers at the solid-liquid interface.
Self-assembly of surface-active agents at solid–liquid interfaces is critical for many processes in nature and technology, including the stability of suspension, detergency, wetting and mineral separation. Historically, a detailed understanding of nanometer-scale layers has emerged. However, surprisingly little is known about their dynamics—the key to non-equilibrium phenomena. Even in equilibr...
متن کاملWater orientation and hydrogen-bond structure at the fluorite/water interface.
Water in contact with mineral interfaces is important for a variety of different processes. Here, we present a combined theoretical/experimental study which provides a quantitative, molecular-level understanding of the ubiquitous and important CaF2/water interface. Our results show that, at low pH, the surface is positively charged, causing a substantial degree of water ordering. The surface ch...
متن کاملStructure, dynamics and stability of water/scCO2/mineral interfaces from ab initio molecular dynamics simulations
The boundary layer at solid-liquid interfaces is a unique reaction environment that poses significant scientific challenges to characterize and understand by experimentation alone. Using ab initio molecular dynamics (AIMD) methods, we report on the structure and dynamics of boundary layer formation, cation mobilization and carbonation under geologic carbon sequestration scenarios (T = 323 K and...
متن کامل